The operator of a Dorchester day-care center housed in an apartment building where a 2-year-old boy fell to his death was surrendering her license Thursday as new details emerged showing repeated violations at the facility.

Marisol Rondon-Ramos, who has been licensed to operate a day care since 2006, has been cited three times by the Department of Early Education and Care for enrolling too many children in her program and four times for noncompliance with safe sleep practices, according to the state.

Relatives said toddler Daylan Walker was at Rondon-Ramos’s day care on Wednesday when he fell from the roof of 129-135 Columbia Road. Police said the boy was found on the pavement behind the building just before 10 a.m. and taken to Boston Medical Center, where he was pronounced dead.

“He was a very good boy,” said Laura Lara, 17, a family friend who used to baby-sit for Daylan. “It’s just hard to accept the fact that he’s gone.”

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His mother, Leonela Rivera, recently graduated from college, Lara said, and had found a job at a chiropractor's office. At first, Lara said, Rivera brought Daylan to work, but put the boy in day care about 2½ weeks ago because her boss told her she could not bring him anymore.

Reports released by the state show Rondon-Ramos complied with regulators’ demands to correct problems found at her program between December 2009 and January 2013. No one answered the phone Thursday at her residence, and security guards kept nonresidents away from the property.

“The Department of Early Education and Care continues to investigate this tragedy in close coordination with law enforcement and the Department of Children and Families,” the agency said in a statement. “Our hearts and prayers are with Daylan’s family as they grieve this unimaginable loss.”

After her most recent citation for overenrollment and noncompliance with safe sleep practices in November 2013, the state restricted Rondon-Ramos’s license so that she could not care for children under 15 months, and the number of children she could care for was reduced to six, the agency said.

Regulators also investigated allegations of child abuse against Rondon-Ramos in June 2012 and January 2013, but did not find evidence to support the claims, the state said. In the June 2012 incident, a parent who made the abuse accusation continued to enroll the child in the program, state officials said.

The sleep-related concerns regulators raised with Rondon-Ramos included letting children sleep in bouncers, letting them sleep in a hallway that was too dark, and letting children sleep in a room that was not approved, state records show.

In a 2013 letter to Rondon-Ramos, the state wrote that she continued to let children sleep in bouncer seats after she said she would stop the practice.

In another letter dated Feb. 4, the state said it met with Rondon-Ramos to discuss overenrollment and sleep issues.

The letter said Rondon-Ramos told regulators that she would reduce the number of children she cared for to six on condition that none of them would be younger than 15 months.

Investigators are reviewing surveillance footage to establish a timeline of what happened when Daylan Walker
went missing, Boston police said.

A spokesman for Suffolk District Attorney Daniel F. Conley said no charges have been sought in connection with the child’s death.

A law enforcement official briefed on the investigation said Daylan had been missing for possibly 20 minutes before he was found on the ground outside the building around 10 a.m. by a woman who lives on the first floor.

The official said people from the day-care center had searched for the boy outside the building, looking on the street and at a nearby Burger King.

“They did not know he went upstairs,” said the official, who asked for anonymity because of the sensitivity of the investigation.

Councilor Tito Jackson said he was told the boy had been seen playing in the hallway.

“We can at this point surmise that this young man for some period of time was unattended,” Jackson said in a telephone interview Thursday afternoon.

“The question I have is why, how long, and literally how could this happen in a day-care setting.”

Daylan’s uncle, Carlos Abel, said Rondon-Ramos’s son greeted the boy when he arrived at day care Wednesday.

“Fifteen minutes later we get a call from police saying the boy is dead,” said Abel, speaking in Spanish.

City inspectors visited the property Wednesday afternoon after the death and issued a citation because the door leading to the roof did not close properly, said William Christopher, commissioner of the Inspectional Services Department.

The battery-operated alarm triggered by pushing the door open with its crash bar was also not functioning, but that did not constitute a violation, Christopher said.

He added that inspectors do not know whether the door was open when Daylan reached the roof.

Chrystal Kornegay, the chief executive and president of Urban Edge, which owns the property as part of a partnership with the Theroch Tenants Association, said she has not been informed of the citation.

The apartment complex comprises 191 units, which are paid for by rental subsidies provided by the Department of Housing and Urban Development.

Kornegay said she has not been made aware of any inspection issues at the property, which is managed by Winn Cos.

“If there were real issues, I would be aware,” Kornegay said.

Chanelia Dorest, who lives on the fourth floor of the building, said she has only seen maintenance staff use the door to the roof.

“That door was always closed,” Dorest said in a telephone interview.

She estimated that there are close to 70 stairs leading up to the fourth floor and then another set of steps to climb to get to the roof.

“I get tired by the time I make it to the third floor,” Dorest said. “The kid had to get all the way up those stairs and push the door open. That’s crazy.”

Daylan lived with his mother in a Dorchester apartment building on Blue Hill Avenue.

Lara, the family friend, recalled that the last time she saw the boy he was playing with the toy trucks he adored. He used to race them up and down her arms shouting “Look, look!” she said.

Daylan was just learning to talk and loved dogs and playing with trucks, she said. He had mastered his ABC’s, counting to 30, and the names of the people he loved the most: Mami, Papi, Abuela, Uncle.

At the building where the day-care center is housed, many began leaving candles, stuffed animals, balloons, and a toy car in his memory on Thursday.

Daylan Walker.

“It’s horrible,” Evelyn Cartwright, 69, said Thursday afternoon, sitting on her front porch across the street from where the boy fell.

“I don’t understand how a child his age could walk from the first floor to the roof and get out there,’’ said Cartwright. “It’s almost impossible.”

Relatives and friends said she was so overcome by grief that she needed medical help at an undisclosed hospital.

Thursday night, mourners and supporters went to the makeshift memorial that grew rapidly on a fence outside the day-care building in remembrance of the boy.

Some members of the boy’s family arrived, and his uncle addressed the crowd in Spanish as many attendees cried and embraced.

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